Background and Purpose: Influenza (flu) causes many hospitalization and death in the year. It is recommended health care workers (HCW) receive the annual flu vaccine. But studies have shown that a few of medical staffs are vaccinated against flu. This study was conducted to determine the incentives and disincentives of flu vaccination in nurses. Methods: This cross-sectional study was conducted among 200 nurses in teaching hospitals in Shahid Sadoughi University in 2011. The Samples were selected randomly. The data collection tool was a 35-point self-administered questionnaire about the incentive and disincentive for flu vaccination. Frequencies, percentages, mean, standard deviation, and chi-square were used for statistical analysis. Results: According to the findings, 32.5% of nurses were vaccinated, the main factors for encouraging vaccination were: personal protection (95%), family safety (25.5%), not being concerned about spreading the disease (18%), and following other health workers (26.5%). The main factors inhibiting for the vaccination were: not believing in the effectiveness of the vaccine (26%), lacking of information about vaccine (31%) and not being worried about flu (26%). Conclusion: Based on the results, the incentives for vaccination in nurses were protection against the disease and the persuasion of other HCWs. The most inhibitors were the high cost of vaccination and lack of knowledge about flu vaccination. It is, therefore, necessary to promote vaccination in nursing staffs by offering more facilities such as vaccination in the workplace, providing free immunizations and educational actions.